A teacher who gave his pupils answers to an exam to cover up his administrative bungling has narrowly escaped having his registration cancelled.

The teacher was found to have committed serious misconduct in having his pupils resit National Certificate of Educational Achievement assessments on the basis that he would provide them with the answers, having lost the paperwork required to validate the assessments they had already sat.

The Teachers Disciplinary Tribunal found that the teacher's conduct undermined the integrity of the qualifications system and had imposed a moral dilemma on his pupils when he asked them not to reveal to their parents or others what was taking place.

The teacher mislaid the relevant paperwork for the assessments during a transitional NCEA phase when assessment standards were updated.

He became aware the pupils would either have to pay a fee of $76.50 to have the expired standards transferred to the current year, plus a $50 late fee, or do extra work and resit the examination for the new standard.

The affected class was summoned to the teacher's classroom, and he advised the pupils that because of his error they would not get credit for their work towards the old standard.

He would correct his error by providing them with the answers to the new assessment to ensure that they were achieved, he told the class.

On the same day, five pupils resat the test and were told by the teacher to keep quiet and use the answers he provided so they did not have to learn everything again.

After the test, three pupils told the deputy principal what had happened, and the deputy principal told the teacher the issue would be investigated and instructed him not to speak to pupils about the issue.

A week later, the teacher said he had changed his mind about handing in answer papers from the test, and told the class the next day.

He asked the pupils who had told the deputy principal about resitting the assessments, causing them to be "nervous and uncomfortable" about the possible consequences, the tribunal's decision said.

Before the tribunal, the teacher admitted to having been disorganised in dealing with the submission of his NCEA assessment work, and he felt a deep sense of responsibility to his pupils when he mislaid the relevant paperwork.

The teacher acknowledged having made "a huge error of judgment" and justified what he did in that the pupils were being awarded the credits they were entitled to have, the decision said.

"The students had reached the required level and in my mind this was just overcoming an inconvenient administrative hurdle," he said.

The tribunal considered his actions a breach of his fundamental responsibilities as a teacher but was convinced the difficulties he faced at the time impaired his judgment.

He had a series of health problems about the end of the 2011 school year when he had been diagnosed with prostate cancer and various complications.

His representative at the tribunal said that at the time of the incident the teacher was "physically unwell, depressed and had lost perspective".

Instead of attempting to "dig his way out of the problem" as he did, he should have sought help, the representative said.

The teacher's record was previously unblemished, and he was full of remorse for his actions.

The tribunal felt able to deal with the teacher in a relatively lenient way, censuring him for his serious misconduct and imposing conditions on his practising certificate for three years, stopping short of cancelling his registration "by a fine margin".

The teacher indicated no desire to work in a secondary school again as the incident had damaged his self-confidence.

The New Zealand Qualifications Authority was initially going to remove credits loaded on the system from the expired standards from the pupils because of the teacher's actions, but decided not to as doing so would disadvantage the pupils through no fault of their own.